As wireless terminals such as a smartphone becomes popular, the traffic of mobile communications is increasing more and more. This consequently causes the capacity shortage of a backbone network and begins to significantly influence on usability for end users.
A possible solution to such a problem is data offloading using Wi-Fi. However, when Wi-Fi is on, the wireless terminal regularly searches for a connectable base station (AP, Access Point) therearound. This consequently causes the wireless terminal to continue power consumption and rapidly exhaust the battery thereof. Therefore, Wi-Fi is usually kept off, so that data offloading is not widespread.
An answer to such a problem is a wakeup system. A wakeup system generally keeps Wi-Fi off and, only when Wi-Fi is available, automatically turns on Wi-Fi, thereby limiting power consumption by Wi-Fi in the reception standby state.
A technique using the wakeup system is disclosed in Patent Documents 1 and 2, for example. Patent Documents 1 and 2 describe a technique of starting a wireless base station and a wireless router with a wakeup signal sent from a terminal. Use of the technique allows a wireless base station and a wireless router to be in the sleep state when not in use and start when in use.
Patent Document 1: Japanese Unexamined Patent Application Publication No. JP-A 2013-162476
Patent Document 2: Japanese Unexamined Patent Application Publication No. JP-A 2013-009431
However, the technique described in Patent Documents 1 and 2 requires a wireless terminal to search for a connectable Wi-Fi base station (AP) and acquire connection information of a channel (ch) and the like when Wi-Fi is turned on. As a result, it takes time before a connection process is executed after Wi-Fi is turned on.
Further, a Wi-Fi base station needs to authenticate an unspecified terminal in Wi-Fi connection. Therefore, a WI-Fi base station needs to acquire necessary information for authentication every time before executing an authentication process, and consequently, it also takes time to execute the authentication process.
Thus, a system which wakes a terminal up and uses Wi-Fi has a problem that it takes time before communication is established.